Altered Cell and Tissue Biology: Macrophages and Acute Inflammation

Altered Cell and Tissue Biology

Macrophages

• Types:
  • M1 (classically activated): pro-inflammatory, antimicrobial
  • M2 (alternatively activated): anti-inflammatory, tissue repair
• Functions:
  • Phagocytosis: engulf and digest foreign particles and debris
  • Antigen presentation: process and present antigens to T-cells
  • Cytokine production: regulate inflammation and immune response
  • Tissue repair: promote healing and tissue remodeling

Acute Inflammation

• Characteristics:
  • Rapid onset and resolution
  • Localized response to tissue injury or infection
  • Increased blood flow, permeability, and immune cell recruitment
• Phases:
  1. Vasodilation: increased blood flow and permeability
  2. Leukocyte recruitment: neutrophils and macrophages migrate to site
  3. Debris removal: phagocytosis and clearance of foreign particles
  4. Tissue repair: restoration of normal tissue architecture

Chronic Inflammation

• Characteristics:
  • Prolonged and persistent inflammation
  • Inadequate resolution of acute inflammation
  • Tissue damage and fibrosis
• Consequences:
  • Tissue remodeling and scarring
  • Impaired organ function
  • Increased risk of cancer and other diseases

HIV/AIDS

• Human Immunodeficiency Virus (HIV):
  • Retrovirus that targets CD4+ T-cells (helper T-cells)
  • Impairs immune function and increases susceptibility to infections
• Acquired Immunodeficiency Syndrome (AIDS):
  • Advanced stage of HIV infection
  • Characterized by severe immunosuppression and opportunistic infections

Primary Immunodeficiency

• Inherited disorders:
  • Defects in immune cell development or function
  • Increased susceptibility to infections
• Examples:
  • Severe Combined Immunodeficiency (SCID)
  • Common Variable Immunodeficiency (CVID)
  • X-Linked Agammaglobulinemia (XLA)

Altered Cell and Tissue Biology

Macrophages

• M1 macrophages: Classically activated, pro-inflammatory, and antimicrobial.
• M2 macrophages: Alternatively activated, anti-inflammatory, and involved in tissue repair.
• Phagocytosis: Engulf and digest foreign particles and debris.
• Antigen presentation: Process and present antigens to T-cells.
• Cytokine production: Regulate inflammation and immune response.
• Tissue repair: Promote healing and tissue remodeling.

Acute Inflammation

• Rapid onset and resolution: Short-lived response to tissue injury or infection.
• Localized response: Increased blood flow, permeability, and immune cell recruitment.
• Vasodilation: Increased blood flow and permeability.
• Leukocyte recruitment: Neutrophils and macrophages migrate to site.
• Debris removal: Phagocytosis and clearance of foreign particles.
• Tissue repair: Restoration of normal tissue architecture.

Chronic Inflammation

• Prolonged and persistent inflammation: Inadequate resolution of acute inflammation.
• Tissue damage and fibrosis: Long-term consequences of chronic inflammation.
• Tissue remodeling and scarring: Irreversible tissue damage.
• Impaired organ function: Consequences of chronic inflammation.
• Increased risk of cancer and other diseases: Chronic inflammation's long-term effects.

HIV/AIDS

• HIV: Retrovirus that targets CD4+ T-cells (helper T-cells), impairing immune function.
• Immune system impairment: Increased susceptibility to infections.
• AIDS: Advanced stage of HIV infection, characterized by severe immunosuppression and opportunistic infections.

Primary Immunodeficiency

• Inherited disorders: Defects in immune cell development or function, increasing susceptibility to infections.
• Examples of primary immunodeficiencies: Severe Combined Immunodeficiency (SCID), Common Variable Immunodeficiency (CVID), and X-Linked Agammaglobulinemia (XLA).